Situated at the mouth of the River Seine, the port city of Le Havre was almost completely rebuilt after World War II. The unusual concrete architecture of Le Havre, designed by Auguste Perret, resulted in the city center becoming a UNESCO World Heritage Site in 2005. Highlights of Le Havre include the Perret show flat, an impressive modern art museum, and a picturesque marina and beach. It is also an important cross-Channel ferry port and the largest container port in France.